Headphones are people's portable stereo. Nowadays, there is an increasingly elaborated requirement on classification of headphones, and selecting appropriate headphones according to different occasions has become a symbol of a fashion lifestyle.
With an increasing requirement on sound quality, headphones such as active noise reduction headphones for improving sound quality frequently appear. The active noise reduction headphones receive an external sound by using a noise reduction microphone integrated on the headphones, and then generate a sound whose phase is opposite to that of external noise, to offset the noise, so that a user can listen to a better sound effect. Therefore, the active noise reduction headphones are especially suitable for people who are often on a business trip, for example, businessmen and office workers, to use in an aircraft cabin, a railway carriage, or a subway in which there is much noise. By using the noise reduction headphones, these users can not only keep away from interference of noise, but can also adjust mood by using the headphones, so as to fully enjoy the trip.
However, the active noise reduction headphones generally need to be powered by an external battery, and further, considering requirements for portability and appearance, there is a specific limitation on a size and weight of the external battery. Consequently, a capacity of the external battery is designed to be small, which cannot meet a requirement for long time use of a user. The user needs to frequently charge the headphones separately, which causes some inconvenience to the user.